Download Human Nervous System

What is a reflex?
An inborn, involuntary, and
automatic response to a specific
stimulus
Why are reflexes
important?
They protect the body – maintain
homeostasis
What are some examples of reflexes?
blinking
pupil constricts in light
knee-jerk
gag
swallowing
Vomiting
Startle
withdrawl
Primitive reflexes – in infants – rooting, sucking
stimulus
receptor
Processing; Decision to respond
Brain
effector
response
Types of Neurons
sensory neurons
- transmit impulses from the receptors
to the spinal cord and brain
interneurons
- relay impulses between sensory and
motor neurons or between other
interneurons
motor neurons
- transmit impulses from the spinal
cord to the effectors
Nerve - a bundle of neurons or the
axons and/or dendrites of neurons
covered with connective tissue
Types of Nerves
sensory nerves
contain the long dendrites of sensory
neurons; transmit impulses away from
receptors to the spinal cord and brain
motor nerves
contain the long axons of motor
neurons; transmit impulses from the
central nervous system to the effectors
mixed nerves
contains both the long dendrites of
sensory neurons and the long axons
of motor neurons
brain
muscle
Sensory neuron
spinal cord
interneuron
motor neuron
stimulus
Label: stimulus, sensory neuron,
interneuron, motor neuron, muscle,
brain, spinal cord
Reflex Arc - pathway over which
impulses travel in a reflex
interneuron


sensory neuron  motor neuron  effector


stimulus
response
Spinal cord
interneuron
Cell body of
Sensory neuron
synapse
motor neuron
Sensory neuron
stimulus
muscle
brain
spinal cord
relays impulses
between the
brain and the
rest of the
nervous system;
coordinates
simple reflexes
Types of Neurons
sensory neurons
- transmit impulses from the receptors
to the spinal cord and brain
interneurons
- relay impulses between sensory and
motor neurons or between other
interneurons
motor neurons
- transmit impulses from the spinal
cord to the effectors
Human
Nervous
System
ganglia - groups of cell bodies (cytons)
and interneurons that switch, relay, and
coordinate nerve impulses
brain
spinal cord
relays impulses
between the
brain and the
rest of the
nervous system;
coordinates
simple reflexes
Peripheral
nerves
Eyes
The
Peripheral Nervous System
Is divided into two types of
neurons called
Central N.S.
Carry
messages
to sensory
motor
Receive
messages
from
sense organs
contains
Examples
include
skin
eyes
ears
contains
The Somatic N.S.
Involved
with
conscious
control of
Skeletal muscle
Which carry
messages to
Muscles and glands
that control
involuntary
activities of the
body are part
of the
Autonomic N.S.
Autonomic N.S.
Two
divisions
include
Sympathetic N.S.
Parasympathetic N.S.
produces
responses
needed for
stress
produces
responses
needed for
calm
white
Central Nervous
System
grey
Spinal
cord
cerebrum
cerebellum
medulla
Organize these terms in a concept map:
from general (top) to specific (bottom)
•
•
•
•
•
•
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Autonomic Nervous system
Central Nervous System
Human Nervous System
Brain
Sympathetic Nervous System
Parasympathetic Nervous System
Somatic Nervous System
Peripheral Nervous System
Spinal Cord
Human Nervous System
How would a gymnast use the
following during a performance?
•
•
•
•
•
Cerebrum
Cerebellum
Medulla
Spinal Cord
Somatic Nervous System